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Open3D MCP server: setup & tool reference

Open3D Viewer for Windows ships a local Model Context Protocol server. Any MCP client can open 3D files, take screenshots, inspect geometry, check printability and edit meshes in the running app. Everything stays on your PC. Looking for the plain-English overview? See AI Tools.

How it works

• The app is the server. While Open3D Viewer is open with AI Tools on, it listens on 127.0.0.1:5717, on your own PC only.
• The bridge speaks MCP over stdio. Clients launch open3d-mcp.exe, which forwards each tool call to the app. On Store installs it's reachable through the app-execution alias %LOCALAPPDATA%\Microsoft\WindowsApps\open3d-mcp.exe.
• Each call needs a token. It's generated per user and shown in Settings → AI Tools, and the bridge passes it as --token.
• Tools act on what's on screen. That's whatever model is open in the viewer. open_file loads a new one, even if the window is minimised.

Requirements: Windows 10 or 11, Open3D Viewer from the Microsoft Store (1.3.4 or later), and an MCP-capable client. The iPhone and Android apps don't include the MCP server.

One-click setup

1. Open Open3D Viewer → Settings → AI Tools and turn it on.
2. Click Install next to your client. Open3D writes the open3d entry into that client's config file and leaves your other servers alone.
3. Fully quit and reopen the client so it loads the new server.
4. Keep Open3D Viewer running while you use it.

Manual config per client

Use this if you'd rather edit the file yourself or your client isn't listed. Replace <token> with the token from Settings → AI Tools, and <user> with your Windows user folder name. In JSON, backslashes must be doubled.

JSON clients (Claude Desktop, Cursor, Windsurf, Antigravity)

{
  "mcpServers": {
    "open3d": {
      "command": "C:\\Users\\<user>\\AppData\\Local\\Microsoft\\WindowsApps\\open3d-mcp.exe",
      "args": ["--token", "<token>"]
    }
  }
}

Zed

Same entry, under context_servers in Zed's settings.json:

"context_servers": {
  "open3d": {
    "command": "C:\\Users\\<user>\\AppData\\Local\\Microsoft\\WindowsApps\\open3d-mcp.exe",
    "args": ["--token", "<token>"]
  }
}

Codex CLI / Codex IDE / ChatGPT Desktop

[mcp_servers.open3d]
command = "C:\\Users\\<user>\\AppData\\Local\\Microsoft\\WindowsApps\\open3d-mcp.exe"
args = ["--token", "<token>"]

HTTP endpoint

For clients that take a server URL instead of a command, Settings → AI Tools shows a one-shot MCP JSON-RPC endpoint:

http://127.0.0.1:5717/mcp?token=<token>

It only listens on localhost. Web-only chat apps (web ChatGPT, web Gemini) can't reach it unless you tunnel it yourself, which isn't recommended. Clients with no MCP support at all can't use it either.

Tool reference

94 working tools. Units are whatever the scene is declared in (get_scene_units). Mesh formats default to millimetres; glTF is converted from metres. Every edit can be undone with undo_edit or reset_edits, and nothing is written to disk unless you call save_edits.

Open, look & inspect

Pins (annotations)

3D-print checks & prep

Repair

Meshes & transforms

Face selection & editing

Materials & textures

Edit history & saving

list_meshes, measure and raycast_screen are listed too but are reserved and return "not implemented yet". Use get_model_info, raycast_ray and distance_to_mesh instead.

Example prompts

• "Open C:\prints\bracket.stl, check it for printing and tell me what would fail."
• "Find walls thinner than 1 mm and show them to me."
• "Fill the holes, make it 80 mm tall, drop it on the bed and save it as bracket_fixed.stl."
• "Make the chair walnut and the legs brushed steel, then screenshot it from the front."

Troubleshooting

"Cannot reach Open3D Viewer"

The app isn't running or AI Tools is off. Open Open3D Viewer, check Settings → AI Tools is on, then retry.

The client doesn't list any Open3D tools

Fully quit the client (including from the system tray) and reopen it. Most clients only read their MCP config at launch. Then check the open3d entry is in the file from the table above.

"Access is denied" starting the server

The config points inside C:\Program Files\WindowsApps. Click Install again in Settings → AI Tools, or switch the command to the %LOCALAPPDATA%\Microsoft\WindowsApps\open3d-mcp.exe alias.

Unauthorized / bad token

The token was regenerated. Re-run Install, or paste the current token from Settings → AI Tools.

Still stuck?

Email [email protected] with your client name and version. AI apps change often, and we fix setup problems quickly.

Privacy & security

• The server binds to 127.0.0.1 only and requires the per-user token.
• Open3D sends nothing to us. What your AI client sends to its own cloud (screenshots, tool results) follows that client's policy.
• Texture tools only read from folders you allow (set_texture_folder). Files are only written when you call save_edits.